Electronic fuzing systems for controlling the detonation of a projectile warhead are well-known in the art. One approach is to utilize projectile-borne sensors of various types, e.g., radar, infra-red, electrostatic, etc., for signalling an electronic fuze to detonate the warhead when the projectile is proximate the target. A variant of this approach is to signal the electronic fuze to detonate the warhead via a microwave link when fire control radar determines that the projectile is within killing range of the target.
Another approach is to determine target range using, for example, a radar or laser range finder, and then set the electronic fuze for an appropriate time-of-flight based on the determined target range. Once the projectile is fired, the electronic fuse counts out the flight time and detonates the warhead when the pre-set time-of-flight expires. Timed fuze detonation, rather that impact or point detonation (PD), is more effective for some targets, such as entrenched ground troops, where warhead detonation while the projectile is overhead will typically have more devastating effects.
One extremely important consideration in setting electronic fuzes is the setting time required, particularly with the current emphasis on rapid-fire cannons. Thus, entering the time-of-flight information into the electronic fuze must be accomplished during an extremely short time window so as not to jeopardize firing rate. Moreover, the setting information must be accurately registered in the electronic fuze, otherwise that projectile becomes a "dud" insofar as the intended target is concerned. Various techniques have been utilized for entering the time-of-flight data from the fuze setter into the fuze, including microwave links to enter this data while the projectile is in flight to the target or travelling down the gun barrel, or inductive coupling links also while the projectile transits the gun barrel. Alternative, a wire data link between the fuze setter and the fuze has been employed.